Method and means for controlling the variations in weight of extruded sausages

ABSTRACT

A conveyor assembly for moving an extruded strand of sausage ( 26 ) from an extruding machine ( 10 ) and for coagulating the outer surface ( 28 ) of the strand ( 26 ) has first ( 48 ) and second ( 49 ) conveyor elements mounted on a frame ( 36 ). The conveyor assembly on the frame ( 36 ) moves from a point of beginning ( 38 ) to a discharge station ( 40 ) and thence back to the point of beginning ( 38 ). A brine fluid circuit is disposed on the frame above the conveyor with a plurality of discharge nozzles thereon to spray brine on a strand of sausage moving with the conveyor assembly. A pair of laser lights ( 88 ) project beams ( 90 ) on the unlinked strand ( 26 ) to determine the diameter thereof. A signal is sent from the lasers to a controller ( 92 ) who compares the diameter of the strand to a predetermined diameter. The controller controls a meat emulsion pump ( 14 ) and causes it to increase or decrease its meat discharge rate to compensate for variations in diameter, and hence weight, between the measured strand and the predetermined strand on file in the controller.

BACKGROUND OF THE INVENTION

In recent times, it has become known to coextrude a strand of sausagematerial which has an inner core of meat emulsion having an outersurface material that can be coagulated to provide an encasement for thestrand. The coagulation normally includes subjecting the extruded strandto a brine solution. The brine is applied immediately after the strandis extruded.

The brine is sometimes sprayed onto the sausage strand as the strand ismoved along an elongated conveyor which is comprised of a plurality ofpivotally interconnected links. Weight control in these processes islargely dependent upon the accuracy of the meat supply. Such coextrusionsystems are therefore often equipped with metering pumps to ensure suchaccuracy. However, intermittent checks of sausage weights are stilloften required. Such checks are simply done by weighing one or moresausages as they come crimp/cut or linked from the linking device. Whenthe weight is off target, the operator may adjust the meat-flowaccordingly. This is more often the case with instable meat-doughs;those are meat formulations which in time differ in consistency. Forinstance English breakfast sausage meat formulations contain rusk. Ruskis an important ingredient comparable to breadcrumbs. When freshly mixedan English breakfast sausage meat-dough is fairly fluid. Gradually ruskstarts to bind the free water in the dough causing the viscosity torise. Most meat supply systems in use today are vulnerable for suchviscosity changes, in the sense that they give various meat outputs. Itis therefor common practice to check and balance the weight consistencyof such sausage processes. This is true for common sausage casingstuffing, as well as for coextrusion processes.

Recently developments in sausage coextrusion technology have led tocoextrusion processes where the brine treatment is prolonged in time.Older processes have brine dwell times of between 1 and 5 seconds. Newerprocesses have brine times of 30 to 90 seconds or more, depending onsausage end-product requirements. Several advantages over the oldermethods are obtained by prolonged brine times, however the practice ofcheck and balance of the weight consistency is more difficult. Theweight of individual sausages in these processes can only be determinedafter the coextruded sausage strand is crimped/cut or linked in thelinking device. When brine times are for instance 60 seconds, at acommon coextrusion speed of 100 cm per second, there are 60 meters ofsausage already coextruded. If the check after the linking devicedictates a change in meat flow, 60 meters of sausage is already offweight. Compared to the older methods, these new methods have therefor aworse weight control.

It is therefore a principal object of the present invention to provide amethod for manufacturing co-extruded food strands with an edible casingin which the previous problems and disadvantages of the knownco-extrusion methods do not occur.

It is a further object of the present invention to provide a novelmethod for reducing the weight variation of co-extruded sausages.

An additional object of the present invention is to create byco-extrusion a substantially uniform layer of a collagen containing gelaround an elongated strand of foodstuff, coagulating said foodstuff bycontacting it with a salt containing brine, and determining the weightvariation accuracy after said co-extrusion but before linking of thecoextruded sausage strand.

These and other objects will become clear from the following descriptionof the present invention.

SUMMARY OF THE INVENTION

The sausage strand is extruded onto a belt or conveyor and carriedthrough a brine shower system for about 40 seconds. The brine is sprayedthrough nozzles onto the sausage while traveling on the belt. Theconveyor is comprised of a plurality of links which have a flatsupporting surface interrupted by a plurality of spaced protrusionswhich channels therebetween to permit brine to fill the channels and toengage the bottom surface of the sausage strand supported on theprotrusions.

The belt is a Multi-Flex chain made from Acetal plastic. The links aresecured with stainless steel pins. Twenty four meters of belt running onfour tiers provide the brine shower dwell time that is required. Theimprovement of this invention is the method of producing a co-extrudedsausage strand, characterized by determining the weight consistency ofsaid strand before linking said strand of coextruded sausage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of the sausage extruder unit and the associatedconveyor;

FIG. 2 is a side elevational view thereof as viewed from the bottom ofFIG. 1;

FIG. 3 is a schematic view of the conveyor unit;

FIG. 4 is an enlarged scale perspective view of the conveyor belt;

FIG. 5 is an enlarged scale sectional view taken on line 5—5 of FIG. 1;

FIG. 6 is an enlarged scale plan view of a conveyor link;

FIG. 7 is a sectional view on line 7—7 of FIG. 6;

FIG. 8 is an enlarged scale partial plan view taken on line 8—8 of FIG.9;

FIG. 9 is a partial enlarged scale side elevational view taken on line9—9 of FIG. 8;

FIG. 10 is an enlarged scale sectional view taken on line 10—10 of FIG.1; and

FIG. 11 is a schematic view of the sensor system.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The term “sausage” as used herein refers to any type of emulsified meatproduct that is formed into sausage or frankfurter links or the like. Adescription of the machine upon which this invention is practiced willfirst be provided. Most of the machine does not of itself comprise theinvention herein.

The numeral 10 designates an existing coextruding machine suitable forthe conveyor of this invention. The numeral 12 is a meat emulsion hopperusing a meat pump machine 14 for pumping emulsified meat. A collagen gelpump 16 has a hopper 18 for receiving the collagen gel. It is connectedby conduit 19 to inline mixer 20. A tube 22 connects the inline mixer 20to the coextruder 24 which is capable of extruding a cylindrical strandof meat emulsion with a collagen gel material on the outer surfacethereof. Coextruder 24 with detachable nozzle 24A is connected by tube25 to the meat pump 14. The conventional coextruded strand of sausage 26(FIGS. 5, 8, and 9) has an emulsified meat material core with thecollagen gel comprising the outer surface 28 thereof. Liquid smoke fromliquid smoke dispenser 30 is used as a coagulation material to coagulatethe outer surface 28 of sausage strand 26. The liquid smoke dispenser 30can be connected in any convenient way such as by line 32 to the inlinemixer 20 (FIG. 1).

A conveyor system 34 is mounted on frame 36 and has a point of beginning38 adjacent the output end of coextruder 24, and a discharge station 40which is located outwardly and downwardly from the point of beginning38. Three sprockets 42 are rotatably mounted on frame 36 and are adaptedto rotate about a horizontal axis. As best shown in FIG. 2, two of thesprockets 42 are vertically disposed with respect to each other belowpoint of beginning 38, and the third sprocket 42 is located on the outerend of a conveyor system 34 adjacent intermediate discharge station 35.

Two vertical shafts 44 are mounted on opposite ends of frame 36. Eachshaft 44 has five rotatably disposed sprockets 46 thereon which areadapted to rotate on shafts 44 about the vertical axis of the shafts.Each set of five sprockets 46 are located in the same parallel plane asone each of the sprockets on the opposite vertical shaft 44. One of theshafts 44 can be driven by motor 44A (FIGS. 1 and 2). An endlessconveyor 48 is circuitiously mounted on the sprockets 42 and 46.

A second conveyor 49 (FIGS. 8, 9) is rotatably mounted on sprockets 49Aand 49B (FIG. 2). Sprocket 49A is adjacent to and below sprocket 42 inintermediate discharge station 35. Conveyor 49 (FIG. 8) is comprised ofa plurality of corrugated parallel wires 49C interconnected by pivotrods 49D. It is seen that conveyor system 34 includes conveyors 48 and49.

At the intermediate discharge station 35, a ramp plate 35A (FIG. 9) issecured to the machine 10 and extends over the conveyor 48 and sprocket42, and thence extends slightly downwardly towards the top of conveyor49. A water nozzle 35B is mounted over ramp plate 35A and is connectedto a source of fresh water (not shown) by tube 35C to spray fresh wateron strand 26.

An inverted v-shaped frame 50 is mounted on frame 36 adjacent dischargestation 40. A drive 51 shaft for the conveyor 49 is located adjacent thedischarge station 40 as best shown in FIGS. 1 and 2.

Conveyor 48 (FIG. 5) is disposed between a plurality of elongatedL-shaped guides 54 which are secured to frame 36. Elongated rails 56mounted on bearings 58 extend longitudinally through the guides. Withreference to FIG. 4, the conveyor 48 is comprised of a plurality ofconveyor segments or links 60 which each have a circular male member 62at one end thereof with a laterally extending connection slot 64. Asemi-circular female slot 66 appears at the end of segment 60 oppositeto circular male member 62. Laterally extending apertures 68 extendthrough the semi-circular female slot 66. Laterally extending pins 70extend through the aperture 68 and thence through the slot 64 tointerconnect the belt segments 60. The apertures 28 permit the segment60 to pivot about the longitudinal axes of aperture 68, and the slot 64permits the segments 60 to have limited pivoted movement about avertical axis passing through the slot 64 so that the conveyor 48 canreverse its direction of travel around sprockets 46. The center portionof each segment 60 is comprised of a flat supporting surface 72 which isin the same plane as the upper surfaces of the circular male member 62and the body of the segment surrounding the female slots 66. The supportsurface 72 has a plurality of projections 72A which are preferablyaligned in rows to create channels 72B therebetween. The projections 72are approximately 0.063 in. square, and 0.045 inches high, thus makingchannels 72B 0.063 in. wide and 0.045 inches deep. A strand 26 one inchin diameter usually will have its lower surface 26A touching 4-6 members72A and will span 4-6 channels 72B. When the channels 72B are filledwith brine, the brine 72C in the channels will engage the bottom surface26A of sausage strand 26.

With reference to FIG. 2, a brine circuit system 74 includes a brinepump 76. A plurality of miscellaneous control valves 78 are imposed inthe brine circuit 74 to selectively control the flow of brine throughthe system. A fluid line 80 extends from pump 76 and includes aplurality of spaced nozzles 82 which, as discussed hereafter, arelocated in a plurality of locations on frame 36 directly above theconveyor 48 (see FIG. 5) to dispense a spray of fluid brine on thestrand of sausage 26.

Brine circuit 74 includes a brine tank 84 which is connected to a brinecollection tray 86 located below the various tiers of conveyor 48, andbelow conveyor 45.

In operation, the meat emulsion hopper 12 is charged with a supply ofmeat emulsion, and the collagen hopper 18 is charged with a quantity ofcollagen gel. Similarly, the liquid smoke dispenser 30 is charged withliquid smoke so that the liquid smoke is combined with the collagen gelwithin inline mixer 20.

The mixture of liquid smoke and collagen gel is transmitted through tube22 to coextruder 24 which conventionally discharges the sausage strand26 with the center core of meat emulsion and an outer surface 28comprised of the collagen gel and liquid smoke. The liquid smoke isadapted to coagulate the collagen gel in the presence of air and a brinesolution. The strand of sausage 26 is discharged from extruder 24 ontothe point of beginning of the conveyor 34. The sausage strand progressesalong the moving conveyor 48 of the conveyor 34 and is moved under aplurality of the nozzles 82 which spray a quantity of brine on themoving sausage strand. The brine-filled channels 72B help the brine toengage the bottom surface 26A of the strand.

The following structure deals primarily with the instant invention. Apair of laser light emitters 88 (FIG. 10) are secured to frame 50adjacent conveyor discharge end 40 and emit blade shaped beams 90downwardly and inwardly towards the strand 26 which has a coagulatedouter surface 28. The beams 90 together span at least 120° of thecircumference of the strand and communicate electronic signals tocontroller 92 (FIG. 11) which converts the signals into across-sectional diameter of the strand 26. The controller 92 isprogrammed to know the size (diameter) of the nozzle 24A being used inextruder 24 through manual engagement of a conventional touch screen 94on the controller. Since the density of the strand is essentiallyconstant, any variations in the diameter of the strand 26 are directlyproportional to the weight or density of the strand per unit length.Thus, if the nozzle 24A is 10 mm in diameter, the controller 92 from thesignal provided by lasers 88 will advise the controller 92 of anyvariations in the diameter of the strand 26 at the discharge end 40 ofthe conveyor 49. If the sensed diameter of the strand 26 has decreased,(such as by stretching of the strand), this decrease will be sensed bythe controller 92 as described above. An electronic signal will be sentfrom the controller 92 to the power input motor 96 of pump 14 toincrease the output of meat emulsion to extruder 24. This will cause thediameter, and hence the weight, of the finished strand 26 at bushing end40 to be increased commensurate with a predetermined diameter of a knownweight consistent with the 10 mm nozzle being used in that program. Theabove procedure is reversed if the sensed diameter of the strand at end40 is oversize.

The controller 92 may be comprised of one or more computers wherein afirst computer performs the mathematics from the signals received fromthe sensors 88 to calculate the diameter of the sensed strand. The firstcomputer can then transmit the measured diameter data to the secondcomputer for comparison to predetermined diameter data, whereupon thesecond computer can exercise control over the pump speed, as required,to compensate for diameter variations. If desired, the second computercan respond to average measured diameter readings, rather thanindividual readings, whereupon the second computer will respond toaverage measured readings rather than individual readings. The lasers88, for example, can receive measured diamenter data from a strand of upto 50 scans per second over a 40 second period, if average diameterswere to be used.

The controller 92 is also operationally connected to the motor 98 oflinker 100 which receives the strand 26 as it leaves conveyor end 40.The controller 92 operates the linker 100 at constant speed for a givennozzle 24A, and automatically increases the rotational speed of linkermotor 98 and pump motor whenever the touch screen 94 is notifiedmanually that a nozzle of different diameter is being used with extruder24.

The foregoing phenomenon is known generally as “machine visioning” or“machine vision technology”. See, e.g., U.S. Pat. Nos. 5,351,078;5,249,045; 5,283,641; 5,119,190; 5,067,012; 4,984,073; 4,929,029; and4,148,061.

The controller 92 coordinates the speed of the rate of discharge of thestrand of sausage 26 with the longitudinal movement of the conveyors 48and 49 as dictated by motor 44A and the conveyor drive 51 so that theelongated strand will normally not be stretched during its movement.

The excess brine from nozzles 82 flows downwardly into the brinecollection tray 86, and thence into brine tank 84 wherein the excessbrine is recirculated through the system.

The controller 92 is also adapted to cause the strand of sausage 26 tomove from the point of beginning 38 to the intermediate dischargestation 35 in approximately 40 seconds to permit the brine sufficienttime to coagulate the outer surface 28 of the sausage strand 26.

When the strand 26 reaches intermediate discharge station 35, it is verymoist from the brine solution. It moves over ramp plate 35A (FIG. 9) andunderneath fresh water nozzle 35B, and thence onto open wire conveyor49. The residual brine on the strand is washed away by the fresh water,and all the water thereon flows by gravity from the strand downwardlythrough the openings between the corrugations in corrugated wire 49C inconveyor 49 for deposit in tray 86.

When the sausage strand 26 reaches the discharge station 40, the outersurface 28 is sufficiently coagulated to provide strength to the sausagestrand where it is received by linker 100 where it is formed into aplurality of lengths at that location.

The present invention provides a process for coagulating co-extrudedcollagen containing gel surrounding an edible food stuffs, i.e.sausages. Co-extrusion methods are mainly being used for co-extrusion ofsausage or sausage like materials. While the instant process relatesparticularly to the manufacturing of sausages, it may also be used inthe production of other collagen coated foodstuffs, such as fish or meatproducts containing vegetable or cheese or both. The term “sausage” asused herein refers to any type of emulsified food product that is formedinto sausage or frankfurter links or the like.

The invention is not limited to collagen coated foodstuffs, but may alsobe applied for co-extruding foodstuffs with a different kind of coatingmaterial such as casein, soy, wheat, cellulose, alginate, chitosan orstarch based gels.

The present invention holds the concept of determining the weightconsistency of the coextruded sausage strand, right after point ofextrusion, before the point of linking the sausage strand. In thismanner corrections to the meat supply may be taken earlier than afterthe weighing of individual sausages after the linking step. This conceptis particularly useful if the outcome the weight check is automaticallytranslated in meat supply changes, by having the weigh determiningdevice be in direct communication with the meat supply system.

One preferred method of determining the weight accuracy of thecoextruded sausage strand is to have weight sensing means installedafter the coextuder which can intermittently determine the weight of aset length of sausage. For instance one meter of the continuous sausagestrand may be weighed every 2 seconds, right after the coextruder, as itmoves along into its path through the brine dwell system. An electronicprogram can than translate weight variation, into commands towards themeat supply system to secure a weight consistent sausage output.

Such electronic program may be likewise used for a second preferredmethod, by which the weight consistency determination, is accomplishedby determining the sausage strand diameter consistency. In this methodan electronic sensing means is employed (an electronic eye or laserbeams 90) to measure the diameter of the sausage strand as it exits thecoextruder. The sausage strand outer volume or its diameter is in directcorrelation with its weight, therefor diameter changes to the coextrudedsausage strand can be measured and translated into commands to the meatsupply system (e.g., pump 14).

It is therefore seen that the conveyor system of this invention willachieve at least its principal objectives.

What is claimed is:
 1. A method of producing an extruded sausage,comprising the steps of extruding a strand of unlinked sausage by meansof a pump, sensing the weight per unit length of the strand by sensingthe outside diameter thereof, comparing the sensed diameter to that of astrand having a predetermined diameter and predetermined weight per unitlength, determining any plus or minus variance between the measureddiameter and increasing or decreasing, respectively, the rate ofdischarge of sausage by the pump to adjust the diameter of asubsequently extruded strand to that of a strand having thepredetermined diameter.
 2. The method of claim 1 wherein the sensingstep is accomplished by means of at least one sensor laser.
 3. Themethod of claim 1 wherein the sensing step is accomplished by means ofat least a pair of laser sensors.
 4. The method of claim 3 wherein thesensors emit a planar beam of light towards the strand.
 5. The method ofclaim 4 wherein the planar beam of light intersects at least 120° of thecircumference of the strand.
 6. The method of claim 1 wherein the strandis formed into a plurality of elongated links after the sensing hastaken place.
 7. A method of producing a co-extruded sausage, comprisingthe steps of, co-extruding a strand of unlinked sausage by means of apump, the co-extruding including co-extrusion of a casing formingmaterial around a strand of meat material, coagulating the casingforming material, determining the weight per unit length of theco-extruded strand after the step of coagulating, and thence, linkingthe strand into a plurality of links, sensing the weight per unit lengthof the strand by sensing the outside diameter thereof, comparing thesensed diameter to that of a strand having a predetermined diameter andpredetermined weight per unit length, determining any plus or minusvariance between the measured diameter and increasing or decreasing,respectively, the rate of discharge of sausage by the pump to adjust thediameter of a subsequently extruded strand to that of a strand having apredetermined diameter.
 8. The method of claim 7 wherein the strand ismoved through a coagulation station after extrusion, and then has itsdiameter sensed.
 9. A method for producing co-extruded sausage includingthe steps of co-extruding a layer of casing forming material around astrand of meat material to form a strand of sausage, coagulating saidcasing forming material and linking said strand of sausage, the methodfurther including the step of determining the weight consistency of saidstrand of sausage before said linking.
 10. A method according to claim 9wherein the determining of weight consistency being performed with theuse of measuring means to determine the diameter of said strand ofsausage.
 11. A method according to claim 2 wherein the use of electronicvision technology to determine the diameter of said strand of sausage.12. A method according to claim wherein said assessment of weightconsistency being performed with the use of sensing means to determinethe weight of a predefined length of sausage.
 13. The method accordingto claim 1 wherein data from said weight sensing step is communicated topumping equipment of said sausage supply, as to automatically vary saidequipment setting to obtain low weight variation of said strand ofsausage.
 14. The method according to claim 1 wherein said co-extrudedstrand of sausage being set in contact with a salt containing solutionfor a period longer than 3 seconds prior to said linking.
 15. The methodaccording to claim 1 wherein said co-extruded sausage being Englishbreakfast sausage.
 16. The method according to claim 15 wherein saidsausage contains rusk.
 17. An apparatus for producing co-extrudedsausage comprising a co-extruder having an infeed and outfeed end, asupply of casing forming material and a supply of foodstuff connected tosaid infeed end to form a strand of co-extruded sausage from saidoutfeed end, and having means to determine weight consistency of saidstrand of co-extruded sausage close to said outfeed end.
 18. The methodaccording to claim 9 wherein said step to assess weight consistencyincludes equipment to determine the diameter of said co-extruded sausagestrand.
 19. The method according to claim 9 wherein said step to assessweight consistency includes equipment to determine the weight of apredefined length of said co-extruded sausage strand.
 20. The methodaccording to claim 9 wherein said step to assess weight consistencyincludes output data in communication with pumping equipment for asupply of the sausage strand as to automatically vary said equipmentsetting to obtain low weight variation of said co-extruded sausagestrand.
 21. The method of claim 7 wherein the sensing step isaccomplished by means of at least a pair of laser sensors.
 22. Themethod of claim 21 wherein the sensors emit a planar beam of lighttowards the strand.
 23. The method of claim 22 wherein the planar beamof light intersects at least 120° of the circumference of the strand.24. The method of claim 7 wherein the strand is formed into a pluralityof elongated links after the sensing has taken place.
 25. An apparatusfor producing co-extruded sausage, comprising, a coextruder forextruding a sausage strand having an inner core and a casing formingmaterial on the outer surface thereof, a meat pump means connected tothe co-extruder and a source of sausage material and casing formingmaterial, a conveyor downstream from the co-extruder to receive theextruded sausage strand, and having a discharge end, means on theconveyor for providing a coagulation solution to the extruded strand, asensor means adjacent the discharge end of the conveyor for determiningthe weight per unit length of the sausage strand, controller meansconnected to the sensor means for comparing the measured weight of thestrand to a predetermined desired weight, the controller beingoperationally connected to the pump means to adjust a flow of meat fromthe pump to compensate for any variance between the measured weight ofthe strand and the said predetermined desired weights during thecontinued operation of the apparatus.
 26. The apparatus of claim 25wherein the co-extruder has a removable discharge nozzle so as to permitthe use of a plurality of nozzles of different diameters.
 27. Theapparatus of claim 25 wherein a linker means is located downstream ofthe sensor means to form links in the strand after it has been sensed bythe sensor means.
 28. The apparatus of claim 25 wherein the sensor meansis a pair of oppositely disposed laser sensors that project laser beamsonto the strand adjacent the discharge end of the conveyor.
 29. Theapparatus of claim 28 wherein the laser sensors emit planar beams oflight towards the strand.
 30. The apparatus of claim 28 wherein thelaser sensors emit planar beams of light towards the strand to determinethe diameter thereof.